1. The Field of the Invention
The present invention relates to cleaning systems, and, more specifically, methods, apparatus, and compositions for cleaning with water, including compositions and dispensers for controlling concentrations of cleaning agents delivered into water.
2. The Relevant Technology
Chemical cleaning agents, in one form or another, have long been used to remove dirt, oil, and particulate matter from a wide variety of articles. Cleaning improves the visual and tactile impression of an article, kills potentially harmful microbes, removes particles that interfere with breathing and vision, and may even extend the life of the article being cleaned. Things such as cookware, homes, automobiles, clothing, and the human body itself stand to benefit from the development of enhanced cleaning agents. Although the present invention contemplates cleaning systems useful for cleaning a wide variety of articles, it is particularly well-adapted for cleaning clothes, as in a washing machine.
Soaps and detergents are two of the most common cleaning agents presently used. While they are often used interchangeably, the words xe2x80x9csoapxe2x80x9d and xe2x80x9cdetergentxe2x80x9d actually denote different classes of compounds.
Soaps are made by a process of saponification wherein a fatty acid reacts with abase to yield the salt of the fatty acid, i.e., a soap. Soap probably has its origin in reacting animal fats, or lard, with alkaline salts, such as wood ash. Today, they are largely synthesized from animal fats and plant oils. Molecules of soap owe their cleaning capacity to their amphiphilic structure, which includes a hydrophobic portion consisting of a long hydrocarbon chain, and a hydrophilic portion composed of an ionic group at one end of the hydrocarbon chain. Because of the hydrocarbon chain, a molecule of soap is not truly soluble in water. Numerous molecules of soap will suspend in water as micelles, or clusters of molecules with long hydrocarbon chains in the inner portions of the cluster, and ionic, water soluble ends facing the polar water.
Because these micelles form hydrophobic centers, they are able to dissolve other non-polar substances, like oils. Once the non-polar, oily dirt is dissolved within the micelles of soap, the ionic surfaces of the micelle repel each other, suspending the oil droplets and preventing them from coalescing. In this fashion, dirt and oil become trapped within the water soluble micelles, and wash away with the water.
A primary disadvantage of soaps is that they form insoluble salts (precipitates) with ions found in hard water. These salts, usually formed when Ca++ and Mg++ ions react with the carboxylate ends of soap molecules, precipitate out of solution as bathtub rings, grits, and other deposits. Water softeners that exchange Ca++ and Mg++ ions for more soluble Na+ ions can alleviate most of this problem.
Most laundry products and many household cleansers actually contain detergents, not soaps. A detergent is a compound with a hydrophobic hydrocarbon chain plus a sulfonate or sulfate ionic end (whereas soaps have carboxylic ends). Because detergents also have an amphiphilic structure, they also form micelles and clean in the same fashion as soaps. However, detergents have the advantage that most metal alkylsulfonates and sulfates are water-soluble. Therefore, detergents do not precipitate out of solution with metal ions found in water. As a result, detergents are not inhibited by hard water. In addition, detergents can be synthesized with continuous chain alkyl groups, which are more easily broken down, or biodegraded, into smaller organic molecules by the microorganisms in septic tanks and sewage treatment plants.
A drawback of most detergents is that they contain additives that take much longer to biodegrade. Some components containing phosphates must be treated in plants. Phosphates therefore promote algae growth, chocking bodies of water and streams. Another disadvantage of detergents is that they can leave behind an undersireable residue even after thorough rinsing.
Detergents are currently used in many household appliances, such as dishwashers and washing machines. Presently, a user must measure out a dose of detergent to add to the cleaning appliance before every cleaning cycle. Conventional packaging and use of detergents creates messy clutter, consumes time, and typically results in a waste of detergent from overdosing. In addition, most washing machines for clothing use a separate rinsing cycle in order to remove the residue. Thus, additional time, water, and heat energy are required to complete the washing process.
It would be a great advancement in the art to provide a novel cleaning system that uses a novel non-detergent composition of cleaner that leaves no residue and therefore, requires no rinsing cycle. Another improvement in the art would be to provide a cleaning agent that is completely biodegradable. Still another improvement would be if this cleaning agent were made from all natural materials. It would also be a great advancement in the art to provide a new method for making a non-detergent cleaning agent. It would be another advancement in the art to provide a cleaning agent that cleans better than the detergents presently on the market. Furthermore, it would be an improvement in the art to simplify the cleaning process and ameliorate the resultant mess with improved, preferably measurement-free or automatic, dosing over many cleaning cycles.
In accordance with the invention as embodied and broadly described herein, an apparatus, composition, and method are disclosed, in suitable detail to enable one of ordinary skill in the art to make and use the invention. In certain embodiments, an apparatus for dispensing cleaning agents in accordance with the present invention includes a vessel comprising a cavity with a cartridge support for mounting a replaceable cartridge.
In one embodiment, the cartridge comprises a novel composition of cleaning agent for cleaning, and solubility control component for controlling the equilibrium concentration of the cleaning composition in solution, further described below. A water source supplies water into the cavity, and a water feed conveys water from the cavity to a cleaning appliance such as a brush, wand, dishwasher, or washing machine for clothing. The apparatus provides a cleaning agent solution in water to the cleaning appliance.
In one embodiment, the inner cavity (and hence the cartridge) of the canister is flooded with water from a water source. The cartridge then dissolves to an equilibrium concentration within the vessel, thus forming a cleaning solution comprising a cleaning agent and a solubility control component to control the concentration of the cleaning agent. The vessel is then purged of the solution, which enters the water feed to be carried into a cleaning appliance.
Enough cleaning solution should be delivered to the feed, to bring the cleaning composition to cleaning concentration when diluted in the washing appliance. Cleaning concentration is the amount of cleaning composition necessary to clean those items serviced by (e.g. placed within) the cleaning appliance during a wash cycle. In particular, a cleaning concentration for a washing machine is that concentration needed to clean a load of clothing. The amount of cleaning composition delivered to the feed is controlled by the amount of cleaning solution and the cleaning solution""s equilibrium concentration. Therefore, the vessel should be configured to receive a predetermined amount of solution, and the solubility control in the cartridge should be configured to dissolve a predetermined equilibrium concentration of cleaning composition in the vessel.
As explained, a composition of cleaner in accordance with the present invention may include a mixture of a cleaning agent and a solubility control agent in a solid state. In some embodiments, the mixture may also comprise an additional alkalinity agent and a water softener. The principal cleaning agent is preferably a gas-releasing compound, e.g. sodium bicarbonate. Gas-releasing compounds clean by reacting with acids (soils) and by mechanical microscrubbing as they yield carbon dioxide. The solubility control agent is preferably a material resistant to dissolving in water, e.g., amorphous silica. These compounds control solubility by dissolving only an equilibrium concentration of composition in solution.
The alkalinity agent is preferably a basic compound found in nature, e.g., sodium sesquicarbonate (which actually contains sodium bicarbonate and sodium carbonate in a substantially 1:1 ratio). The alkalinity agent prevents the cleaning agent from releasing carbon dioxide too quickly by increasing the pH of the solution. The water softener is preferably a naturally occurring material capable of solvating hard water ions, e.g., natural zeolite. The water softener prevents hard ions from reacting with other components to form insoluble salts.
The composition of cleaner may be formulated and cured into various shapes; however, a cylindrical cartridge with an annular cross section is presently preferred. The annular shaped cylinder has an advantage over other shapes in that, as it dissolves, it retains approximately the same surface area, and hence the same dissolution rate. This is because the annular shape yields an interior surface that increases in area at approximately the same rate as that of the exterior surface decreases.
The amount of solubility control component in the composition determines the equilibrium concentration of the composition in a solution, e.g., water. Therefore, the amount of solubility control component should be sufficient to yield a predetermined equilibrium concentration of composition. Similarly, the amount of cleaning agent should be sufficient to provide a predetermined amount of gas in solution. The amount of alkalinity agent should be sufficient to provide a predetermined pH in solution. The amount of water softener should be sufficient to soften household water in solution.
In certain embodiments, a method for making a composition of cleaner in a solid state may include providing a solvent, providing a gas-releasing agent, and providing a solubility control component. The method may also include providing an alkalinity agent. The fabrication process may typically include applying energy, mixing, and testing the composition for an equilibrium concentration. Completion of the process may include casting the composition in a shape selected to control surface area, cooling the composition, and curing the composition.
In other embodiments, a method for using an apparatus for delivering solvated cleaning agents to a cleaning appliance may include providing a dispensing apparatus, shutting off a water supply, opening the dispensing apparatus, installing a shaped block of a cleaning agent, and closing dispensing apparatus. Thereafter, the method may include turning water supply on, running wash cycles, and selectively dissolving a portion of the cleaning agent at a controlled rate with each fill cycle.
In certain embodiments of the present invention, a method for delivering cleaning solution to a cleaning appliance may include flooding a dispensing apparatus with a solvent, dissolving a portion of a hardened charge of cleaning agent, equilibrating a solution of cleaning agent, and flushing the dispensing apparatus. The method may include delivering a cleaning agent solution to a cleaning appliance, cleaning through basic reactions and gas release, and draining waste from the cleaning appliance.
These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.